From 1aa4cb3a3cd1280c04360d5504a3d9e15e52aa22 Mon Sep 17 00:00:00 2001
From: Richard Kenner <kenner@gcc.gnu.org>
Date: Tue, 13 Apr 1993 06:48:10 -0400
Subject: [PATCH] (layout_union): Handle QUAL_UNION_TYPE.

(layout_type): Call layout_union for QUAL_UNION_TYPE and treat it
like UNION_TYPE elsewhere.

From-SVN: r4119
---
 gcc/stor-layout.c | 41 ++++++++++++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 11 deletions(-)

diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index f57c69ef726..c0efe3dab89 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -518,7 +518,7 @@ layout_record (rec)
   return pending_statics;
 }
 
-/* Lay out a UNION_TYPE type.
+/* Lay out a UNION_TYPE or QUAL_UNION_TYPE type.
    Lay out all the fields, set their positions to zero,
    and compute the size and alignment of the union (maximum of any field).
    Note that if you set the TYPE_ALIGN before calling this
@@ -541,6 +541,12 @@ layout_union (rec)
   register int const_size = 0;
   register tree var_size = 0;
 
+  /* If this is a QUAL_UNION_TYPE, we want to process the fields in
+     the reverse order in building the COND_EXPR that denotes its
+     size.  We reverse them again later.  */
+  if (TREE_CODE (rec) == QUAL_UNION_TYPE)
+    TYPE_FIELDS (rec) = nreverse (TYPE_FIELDS (rec));
+
   for (field = TYPE_FIELDS (rec); field; field = TREE_CHAIN (field))
     {
       /* Enums which are local to this class need not be laid out.  */
@@ -561,17 +567,28 @@ layout_union (rec)
 	union_align = MAX (union_align, TYPE_ALIGN (TREE_TYPE (field)));
 #endif
 
-      /* Set union_size to max (decl_size, union_size).
-	 There are more and less general ways to do this.
-	 Use only CONST_SIZE unless forced to use VAR_SIZE.  */
+      if (TREE_CODE (rec) == UNION_TYPE)
+	{
+	  /* Set union_size to max (decl_size, union_size).
+	     There are more and less general ways to do this.
+	     Use only CONST_SIZE unless forced to use VAR_SIZE.  */
 
-      if (TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
-	const_size = MAX (const_size, TREE_INT_CST_LOW (DECL_SIZE (field)));
-      else if (var_size == 0)
-	var_size = DECL_SIZE (field);
-      else
-	var_size = size_binop (MAX_EXPR, var_size, DECL_SIZE (field));
-    }
+	  if (TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
+	    const_size
+	      = MAX (const_size, TREE_INT_CST_LOW (DECL_SIZE (field)));
+	  else if (var_size == 0)
+	    var_size = DECL_SIZE (field);
+	  else
+	    var_size = size_binop (MAX_EXPR, var_size, DECL_SIZE (field));
+	}
+      else if (TREE_CODE (rec) == QUAL_UNION_TYPE)
+	var_size = fold (build (COND_EXPR, sizetype, DECL_QUALIFIER (field),
+				DECL_SIZE (field),
+				var_size ? var_size : integer_zero_node));
+      }
+
+  if (TREE_CODE (rec) == QUAL_UNION_TYPE)
+    TYPE_FIELDS (rec) = nreverse (TYPE_FIELDS (rec));
 
   /* Determine the ultimate size of the union (in bytes).  */
   if (NULL == var_size)
@@ -827,6 +844,7 @@ layout_type (type)
       break;
 
     case UNION_TYPE:
+    case QUAL_UNION_TYPE:
       layout_union (type);
       TYPE_MODE (type) = BLKmode;
       if (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
@@ -893,6 +911,7 @@ layout_type (type)
   if (TYPE_MODE (type) != BLKmode && TYPE_MODE (type) != VOIDmode
       && (STRICT_ALIGNMENT
 	  || (TREE_CODE (type) != RECORD_TYPE && TREE_CODE (type) != UNION_TYPE
+	      && TREE_CODE (type) != QUAL_UNION_TYPE
 	      && TREE_CODE (type) != ARRAY_TYPE)))
     TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type));
 
-- 
2.30.2